A marine drilling riser is a large-diameter pipe that connects a subsea blowout preventer (BOP) stack to a floating surface rig to take mud returns to the surface. Without the riser, the mud would simply spill from the top of the stack onto the seafloor.
The riser has a significant weight which is supported by its own structure and the surface rig. To reduce the weight of the riser acting on the rig, it is known to provide drill riser buoyancy modules along the length of the riser. However, the applicant has determined that in the storage, handling and deployment of drilling risers, there is often mechanical damage inflicted upon the buoyancy and, in cases where riser joints have no buoyancy, damage to the auxiliary lines or pipes of the riser itself. Furthermore, the applicant has determined that existing riser joints may be damaged during stacking and/or may not stack well.
Covers for buoyancy modules have previously been suggested, however, assembly and securement of these covers to the buoyancy modules has not been ideal. In this regard, it is desirable that the covers are easily fixable to the buoyancy modules in a secure manner and offer a flush finish free from snagging edges.
Examples of the invention seek to provide an improved marine drilling riser protection system which overcomes or at least alleviates disadvantages associated with existing systems.